Japanese Laid-Open Patent Publication No. 2012-224230 describes a conventional example of a tire pressure monitoring system. In the system, a tire pressure detector is attached to each tire to detect the pressure of the tire. A receiver is mounted on the body of the vehicle to receive a tire pressure signal transmitted from each tire pressure detector through wireless communication. In such a system, the ID of each tire needs to be registered in advance to the receiver in association with the position of the corresponding tire so that the tire can be located when low pressure is detected.
In the tire pressure monitoring system, the tire ID needs to be registered to the receiver whenever tires are changed, for example, in accordance with the season. This is burdensome.